#ifndef _WX_UNIX_PIPE_H_
#define _WX_UNIX_PIPE_H_

#include <unistd.h>

#include "wx/log.h"
#include "wx/intl.h"

// ----------------------------------------------------------------------------
// wxPipe: this class encapsulates pipe() system call
// ----------------------------------------------------------------------------

class wxPipe {
  public:
    // the symbolic names for the pipe ends
    enum Direction {
      Read,
      Write
    };

    enum {
      INVALID_FD = -1
    };

    // default ctor doesn't do anything
    wxPipe() { m_fds[Read] = m_fds[Write] = INVALID_FD; }

    // create the pipe, return TRUE if ok, FALSE on error
    bool Create() {
      if( pipe( m_fds ) == -1 ) {
        wxLogSysError( _( "Pipe creation failed" ) );
        return FALSE;
      }
      return TRUE;
    }

    // return TRUE if we were created successfully
    bool IsOk() const { return m_fds[Read] != INVALID_FD; }

    // return the descriptor for one of the pipe ends
    int operator[]( Direction which ) const { return m_fds[which]; }

    // detach a descriptor, meaning that the pipe dtor won't close it, and
    // return it
    int Detach( Direction which ) {
      int fd = m_fds[which];
      m_fds[which] = INVALID_FD;
      return fd;
    }

    // close the pipe descriptors
    void Close() {
      for( size_t n = 0; n < WXSIZEOF( m_fds ); n++ ) {
        if( m_fds[n] != INVALID_FD ) {
          close( m_fds[n] );
          m_fds[n] = INVALID_FD;
        }
      }
    }

    // dtor closes the pipe descriptors
    ~wxPipe() { Close(); }

  private:
    int m_fds[2];
};

#if wxUSE_STREAMS && wxUSE_FILE

#include "wx/wfstream.h"

// ----------------------------------------------------------------------------
// wxPipeInputStream: stream for reading from a pipe
// ----------------------------------------------------------------------------

class wxPipeInputStream : public wxFileInputStream {
  public:
    wxPipeInputStream( int fd ) : wxFileInputStream( fd ) { }

    // return TRUE if the pipe is still opened
    bool IsOpened() const { return !Eof(); }

    // return TRUE if we have anything to read, don't block
    virtual bool CanRead() const;
};

#endif // wxUSE_STREAMS && wxUSE_FILE

#endif // _WX_UNIX_PIPE_H_

